This article explores the history, types, famous locations, laws and regulations regarding red light districts in Japan. Red light districts have existed since the Edo period (1603-1868) and there are two main types today: traditional red-light districts near train stations or main roads and modernized red-light districts in large cities such as Tokyo or Osaka. Famous areas include Kabukicho district in Tokyo's Shinjuku ward, Roppongi, Shibuya, Ikebukuro, Yokohama's Isezakicho and many more. Laws governing these establishments must be followed such as no entry for anyone under 18 years old and it is important to exercise caution when visiting any type of adult entertainment establishment.